Re: MSVC hook function prologue

[Paolo Bonzini]

I guess the error isn't about the const_int 0, but about operand 0. Any ideas?

Yes, you need this:

    [(set (match_operand:SI 0 "register_operand" "=r")
          (match_operand:SI 1 "register_operand" "r"))
     (unspec_volatile [(const_int 0)] UNSPECV_VSWAPMOV)]

Paolo